Study Explores 4DCT Ventilation for Preoperative Assessment in Early Lung Cancer

Early-stage lung cancer is commonly treated with surgery in patients who have adequate pulmonary reserve. Preoperative assessment of lung function is important because impaired function can increase the risk of poor postoperative outcomes. Conventional imaging methods such as MRI or CT are not routinely used for this purpose because of limitations related to cost, contrast requirements, and accuracy. Researchers have now evaluated four-dimensional computed tomography ventilation as a preoperative method for assessing lung function before surgery.

Researchers at Thomas Jefferson University (Philadelphia, PA, USA) evaluated four-dimensional computed tomography (4DCT)-ventilation in patients with early-stage lung cancer before surgery. The modality is already used in radiation oncology, but this study marked its first evaluation in a surgical trial. During 4DCT imaging, patients inhale and exhale while scans capture lung motion over time. The resulting images are processed into ventilation maps showing which regions of the lungs function well and which do not.

The pilot study included 30 patients with early-stage lung cancer who were eligible for surgery. Because the 4DCT-ventilation analysis was performed after the trial, the results did not influence clinical decision-making. Months after surgery, researchers compared predicted postoperative lung function from the conventional method with predictions from 4DCT-ventilation. Overall accuracy was similar between the two approaches, but 4DCT-ventilation performed better in patients with uneven lung function, including those who may have chronic obstructive pulmonary disease or emphysema.

The findings were published in the International Journal of Radiation Oncology, Biology, Physics as part of the LIME Trial. The researchers noted that preoperative 4DCT-ventilation could eventually help guide surgical decision-making, although further validation is needed. Future studies are planned in patients with borderline or reduced lung function to assess whether the approach can better determine eligibility for surgery.

“The conventional method of predicting lung function before surgery assumes that lung function is evenly distributed. For patients with conditions affecting lung function, the portion you remove during surgery might not be functioning well, or it might be the only portion that's working very well, which would be detrimental to remove,” said Lydia Wilson, Ph.D., the study's first author and a member of Sidney Kimmel Medical College.

“The hope is that 4DCT-ventilation is better than existing techniques and could remove the need for imaging modalities that are less patient-friendly, take longer, cost more or require contrast,” added Wilson.

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